steps

Download template and print secret messages on waterproof paper. This floatable paper is ink-jet and laser-printable, it uses most inks, and inks won't run on this paper. Cut out message and roll it up.

In a large bowl, combine 1 cup of baking soda and 1/2 teaspoon essential oil.

In a spice or coffee grinder, grind 1/2 cup citric acid, 1/4 cup bath salt, and 2 drops food coloring. Grind to a fine powder, and add to the mixture in the large bowl. Begin whisking together thoroughly.

To mixture, add a couple of sprays of water. It should reach a crumbly consistency.